QmlJS: Allow 'follow symbol' to jump to the target of a file import.

Task-number: QTCREATORBUG-1736

src/libs/qmljs/qmljsbind.cpp

@@ -181,6 +181,7 @@ bool Bind::visit(AST::Program *)
 bool Bind::visit(UiImport *ast)
 {
     ImportInfo info;
+    info.ast = ast;
 
     if (ast->versionToken.isValid()) {
         const QString versionString = _doc->source().mid(ast->versionToken.offset, ast->versionToken.length);

src/libs/qmljs/qmljsbind.h

@@ -54,6 +54,7 @@ public:
     struct ImportInfo {
         QString name;
         ComponentVersion version;
+        AST::UiImport *ast;
     };
 
     QList<ImportInfo> fileImports() const;